/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/DynamicMesh3.h
Tests whether splitting the given vertex with the given triangles would leave no triangles attached to the original vertex (creating an isolated vertex)
true if calling SplitVertex with these arguments would leave an isolated vertex at the original VertexID
virtual bool SplitVertexWouldLeaveIsolated ( int VertexID, const [TArrayView](API\Runtime\Core\Containers\TArrayView)< const int > & TrianglesToUpdate )